The rise in venture capital funding in 2013 is proving that the industry still has legs despite hitting a post-recession trough in 2009. Venture capitalists invested $29.4 billion in 3,995 deals in 2013, an increase of 7 percent in dollars and a 4 percent increase in deals over the prior year, according to the PwC/NVCA MoneyTree™ Report.

The boost came from Internet companies, which captured $7.1 billion, the highest level of Internet investment since 2001. Investments into Software also reached the highest level since 2000.

Investments in seed and early stage companies rose by the double-digits, at 14 percent and 17 percent, respectively; while expansion and later stage rose by only 4 and 1 percent, respectively.

For companies receiving venture capital for the first time, there was a 14 percent rise in dollars while the number of deals increased 3 percent compared to 2012. Industries receiving the most dollars in first-time financings in 2013 were Software, Biotechnology and Media & Entertainment.

Below is PitchBook's listing of the most active venture firms funding seed and early-stage companies in the U.S. To view the research platform's full VC 100 list, click here.

Before the SXSW panel Against All Odds: Overcoming Startup Challenges, panelists share a few insights on the benefits and limitations of new, innovative fundraising models, as well as how to survive in a heavily regulated industry.